1. Field of the Invention
The present invention relates generally to a fuser roller wiper and, more particularly, to a system and drive arrangement for using fuser temperature cycling to change rotational position of the fuser roller wiper.
2. Description of the Related Art
A fuser unit is a common part of a printer, copier, or other printing device that melts and adheres toner onto print media. The print media passes between components in the fuser unit where heat and pressure bond the toner to the print media. The fuser unit typically includes a hot roll and a backup roller that form a fuser nip. The fuser nip is where one roll touches another and print media pass between them through driving contact with them. The hot roll is typically driven, along with several in-feed and out-feed rolls, by a drive system of the fuser unit to transport the print media to and from the nip. The drive system typically includes a fuser motor mounted to a frame of the fuser unit and operatively connected to the hot roll and other rolls by a drive train which includes gears, belts and the like.
Heretofore, a replaceable wiper bar has been provided in the fuser unit above the hot roll to both clean and lubricate the hot roll and thereby to help extend the life of the fuser unit. Especially when a printer is running labels, the wiper bar is needed to wipe contaminants from the hot roll and to apply oil (or wax) to the hot roll to keep it lubricated to help protect it against top coats and adhesives used in label construction. Since only a limited amount of oil (or wax) can be loaded into the felt wiper bar, it is recommended that users change the wiper bar twice during the life of a fuser unit. Users often neglect to do this, shortening the useful life of the fuser unit.
The provision of a permanent or non-replaceable fuser roller wiper in place of the replaceable wiper bar has been proposed to provide an effective means to both clean and lubricate the hot roll throughout its useful life and thus obviate the problem created by users not following the recommendation for periodic replacement of the wiper bar. One such fuser roller wiper is described and illustrated in U.S. Pat. No. 6,875,164 to Lebhold et al. The Lebhold patent discusses the importance to meter a precise amount of release agent per revolution of the hot roll. One of the factors mentioned is the speed of the fuser roller wiper relative to the hot roll. However, this patent does not provide any guidance of how to rotate the fuser roller wiper.
Consequently, there is a need for an innovation that will provide an effective way to rotate the fuser roller wiper so that it will be effective in both cleaning and lubricating the hot roll of a fuser unit.